Marine railway.



'No. 696,723. Patented A r; I, I902.

C. M. DAVIS.

MARINE RAILWAY.

(Application filed May 1, 1901.) (No Model.)

2 Sheets-Sheet I.

- Invenior: g

No. 696,723. Patented Apr. l, I902. c. M. DAVIS.

MARINE RAILWAY.

(Application filed May 1, 1901.)

(N0 Model.)

m: "cams PEYERS co PNOTO-LITHQ. WASHINGTON u. c.

UNITED STATES PATENT @EETCE.

CHARLES M. DAVIS, OF OAMBRIDGEPORT, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO JAOINTI'IO S. CONDINIIO, OF EAST CAMBRIDGE, MASSA- CHUSETTS.

M A R l N E RAILWAY.

SI EGIFICATION formingpart of Letters Patent No. 69 5,723, dated. April 1, 1902. Application filed May 1,1901. Serial No. 58,238. (No model.)

To aZZ whom it may concern.-

Be it known that 1, CHARLES M. DAVIS, a citizen of the United States, residing at (Jambridgeport, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Marine Railways; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled IO in the art to which it appertains to make and use the same.

The present invention relates to marine railways, and has for its object to provide a simple arrangement of dock and traveling I5 carriage whereby a vessel may be removed from the water for the purpose of having its bottom cleaned, painted, or repaired.

Prior to the'present invention it has been proposed to provide an inclined dock or wharf, along which traveled a carriage, the lower end of the dock being beneath the low-water mark and the carriage being adapted to be placed under the vessel and then drawn back up the incline, whereby to bring the vessel out of the water above the high-water mark to permit Work to be done beneath the bottom of the vessel. Such devices as heretofore constructed have been provided with safety devices, such as pawls and ratchets, for preventing the aco cidental downward movement of the carriage; but in such devices should the pawls catch there was great liability of the carriage tipping upward under the great strain incident to the immense weight imposed by the vessel supported thereon. Furthermore,there was but a single set of pawls employed, which were compelled to perform the double duty of holding the carriage and vessel at any point to which they may have been drawn up the inclined dock and also to act as a safety device in case of the breakage of the cable or the disarrangement of the engine or hoisting mechanism. In the present invention there are provided suitable means for preventing the tipping of the carriage and also a double set of pawls, one set being gravitypawls, which operate when the carriage is traveling up in order to hold it at any point to which it may be raised, and another set operated automatically by suitable mechanism and brought into play by the release of draft on the lifting-cable, whereby to hold the cargine become disabled.

The present invention consists of the devices and combination of devices which will be hereinafter described and claimed.

The present invention is illustrated in the accompanying drawings, in which Figure 1 shows the same in side elevation. Fig. 2 shows an end elevation of the carriage and a portion of the dock. Fig. 3 shows a transverse sectional view taken on the dotted line at m, Fig. 1. Fig. at shows a plan View, and Fig. 5 a longitudinal sectional View, through the carriage and a portion of the inclined dock, illustrating the operation of the draft-bar and the safety-pawls. Fig. 6 shows a broken perspective view of one arrangement of the gravity-pawls, to be hereinafter referred to.

Similar reference numerals will be employed to designate corresponding parts.

In the drawings, 1 is the pier, and 2 the inclined dock extending therefrom into the water at any suitable or desired angle. The pier and dock may be constructed in any of the usual Ways of marine construction and may be of a pile construction, as shown, or of masonry, as desired.

Upon the inclined dock 2 are secured longitudinal stringers 3, carrying suitable rails 4, any desired number of stringers and rails being employed, there being three in the construction as illustrated, extending in parallel alinement the entire length of the inclined dock 2. Upon the rails 4 is mounted a traveling carriage 5, which is substantially constructed of wood or steel of suficient strength and of a size suitable to receive and support the vessel or ship V, the said vessel being held thereon by suitable blocks or chocks 7, arranged in any suitable manner to be moved and held in contact with the sides of the vessel.

The device as so far described may be constructed in any of the usual and ordinary riage should the lifting-cable break or the enways and in and of itself forms no part of the present invention. A detailed description of the same is therefore unnecessary.

The carriage 5 is provided with wheels 6, which rest upon the rails 4 and along which they freely travel. The carriage 5 is moved up and down the inclined deck 2 by means of a chain or cable 8, which is wound about the drum 9, actuated by any suitable engine or other suitable source of power 10.

In order to insure that the carriage 5 will be held at all points while it is being drawn up the inclined dock 2, I have provided the usual gravity pawls or'dogs 11, which are piv otally connected to the carriage 5 over the rack 12, preferably located adjacent to the central rail. If desired, there may be similar racks and pawls located adjacent to the side rails. The pawls 11 rest upon and drag along the rack 12 as the carriage 5 is being drawn up the inclined dock 2; but when the carriage is being lowered such pawls must be raised from the rack 12. For the purpose of raising them they are provided with upwardly-extending arms 13 above their ful- .crnms, which are'connected to a chain or cable 14, which at the forward end of the carriage passes overa pulley 15 and is connected to a lever 16, pivotally mounted upon the carriage 5, (see Fig. 2,) the arrangement being such that by swinging lever 16 the pawls 11 may be quickly raised orlowered,asdesired. Another set of pawls 17 are also pivotally mounted upon the carriage 5 over the rack 12 and are designed to be normally held out of contact with said rack duringthe time that draftis applied to the cable 8 and to be automatically thrown into engagement with said rack when the weight upon the cable slackens, as by the breaking of said cable or the disarrangement of the engine. To secure this desired result, the pawls 17 have upwardly-extending ends 18, which are pivotally connected to a bar or rod 19, whereby a rocking of one pawl will cause the others to rock also. The arm 18 of the pawl at the forward end of the carriage 5 is connected by a rod 20 to a hook 21, carried by a headed draw-bar 22, which is fitted to have a movement against the tension of the spring 23 in a cylindrical chamber 24, supported by the yoke 25, fastened to the forward end of the carriage 5. The forward end of the draw-bar 22 is connected by suitable means with the cable 8.

The above-described arrangement is such that a pull upon the cable 8 draws out the draw-bar 22, comprising the spring 23, and through the rods 20 and 19 raising the pawls 17, and should the pull upon the cable slacken the spring 23 acts to throw the pawls 17 into engagement with the rack 12.

I consider the feature just described to be an important part of my invention.

Heretofore in devices of this character the carriage has simply rested upon the rails, and when the pawls engage the racks the force of the sudden bringing up or stopping ofthe.

carriage would cause a lifting upward of the carriage and its displacement, which was a source of much danger and damage. In the present invention I propose to obviate this by providing means for positively holding the carriage in contact with the rails 4, and this I do by means of upper rails 26, which may be supported in any convenient manner, as by means of outwardly-curved arms 27, which are secured to the outer sides of the stringers 3, the carriage 5 carrying grooved rolls or wheels 28, which engage the under surface of the rails 26. It will be noted that by this arrangement it is impossible to cause an upward tipping movement of the carriage and that it will be caused to move in a fixed line up and down the inclined dock 2.

It is thought that the operation of my invention has been sufficiently disclosed in connection with the foregoing description of its construction and arrangement and that further description is unnecessary.

Having described my invention, I claim as new and desire to protect by Letters Patent of the United States In a marine railway, the combination with an inclined dock provided with suitable rails, of a ship-carriage arranged to travel along said rails, a plurality of gravity-pawls arranged to engage and drag along a rack during the upward travel of said carriage along said dock, connected means for simultaneously raising said gravity-pawls and maintaining them raised during the downward travel of said carriage, means for raising and lowering said carriage along said dock, a set of auxiliary spring-actuated pawls, and connections between the spring-actuated pawls and the means for actuating the carriage, arranged to permit said pawls to be thrown into engagement with the rack upon the breaking or disarrangement of the carriageactuating means, substantially as described.

In testimony whereof I aflix my signature in presence of two witnesses.

CHARLES M. DAVIS.

Witnesses:

T. HART ANDERSON, E. M. TINKINGTON. 

